Libby later received the Nobel Prize in Chemistry in 1960 for the radiocarbon discovery.
Today, there are over 130 radiocarbon dating laboratories around the world producing radiocarbon dates for the scientific community.
We know that it is older than Christendom, but whether by a couple of years or a couple of centuries, or even by more than a millenium, we can do no more than guess." [Rasmus Nyerup, (Danish antiquarian), 1802 (in Trigger, 19)].
The person who wrote these words lived in the 1800s, many years before archaeologists could accurately date materials from archaeological sites using scientific methods.
The relative dating method worked very well, but only in sites which were had a connection to the relative scale. When radiocarbon dating was developed, it revolutionised archaeology, because it enabled them to more confidently date the past, and to build a more accurate picture of the human past.
The archaeologist Colin Renfrew (1973) called it the development of this dating method 'the radiocarbon revolution' in describing its great impact upon the human sciences.
The radiocarbon method was developed by a team of scientists led by the late Professor Willard F.
Libby of the University of Chicago after the end of World War 2.
Therefore, radiocarbon dating is not able to date anything older than 60 or 70 000 years old.
Rasmus Nyerup's quote reminds us of the tremendous scientific advances which have taken place in the 20th century.
In Nyerup's time, archaeologists could date the past only by using recorded histories, which in Europe were based mainly on the Egyptian calendar.
During the period of a plant's life, the plant is taking in carbon dioxide through photosynthesis, which is how the plant makes energy and grows.
Animals eat plants, and some eat other animals in the food chain.